CN100542198C - A kind of discrete multi-audio frequency modulation data transmitting method and system - Google Patents

Abstract

The invention discloses a kind of discrete multi-audio frequency modulation data transmitting method and system, this method comprises: A, transmitting terminal are according to the line speed scheme of data message to be sent, generate first table of bits, described first table of bits comprises each circuit carry data information when this sends data; B, transmitting terminal are sent to receiving terminal according to first table of bits after with data-modulated; C, receiving terminal carry out demodulation according to first table of bits, obtain corresponding data.The data transmission method of DMT modulation system provided by the invention and system, by the variable circuit carry data information of dynamic bit table (BIT table) carrying, the transmitted power of line speed and circuit is adjusted according to circuit information transmitted rate is dynamic, instant, can be saved line resource and power resource.

Description

A kind of discrete multi-audio frequency modulation data transmitting method and system

Technical field

The present invention relates to the communications field, relate in particular to a kind of discrete multi-audio frequency modulation data transmitting method and system.

Background technology

XDSL is a kind of high speed data transfer technology that goes up transmission at twisted pair telephone (unshielded twisted pair UTP Unshielded Twist Pair), Digital Subscriber Loop (DSL except baseband transmission such as IDSL and SHDSL, Digital Subscriber Line) outside, the xDSL of passband transmission utilizes frequency multiplexing technique to make xDSL and Plain Old Telephone Service (POTS) coexist as with on a pair of twisted-pair feeder, wherein xDSL occupies high band, POTS takies the following baseband portion of 4KHz, and the POTS signal separates by separator with the xDSL signal.The xDSL of passband transmission adopts Discrete multi-tone modulation (DMT).The system that provides multichannel xDSL to insert is called DSL couple in multiplexer (DSLAM), and its system reference model as shown in Figure 1.

XDSL has determined a speed when opening, such as the line speed of descending 2M; Or the xDSL transceiver the training in determined a line speed according to the circuit situation, such as 4M.As long as this speed is in case determine that in the course of work of reality, no matter how much speed of business data flow is, always line speed is constant, this will be very dumb when the needs reduction error rate.

Technically, keep identical line speed all the time, the transmitted power on the circuit can not change all the time so.For example, circuit definite line speed and resultant signal transmitted power in training is respectively R ₀And P ₀If can information transmitted be I when making full use of line speed ₀, then $\mathrm{IPR}=\frac{I_0}{{\mathrm{<figure-callout\; id="0"\; label="P"\; filenames="C20061000083800211.png,C20061000083800212.png"\; state="\{\{state\}\}">P</figure-callout>}}_0}$ Be circuit information transmitted power ratio.If but be R at line speed ₀Situation under, information transmitted I＜I ₀, owing to keep line speed R ₀Must use resultant signal transmitted power P ₀Constant.At this moment $\mathrm{IPR}=\frac{\mathrm{<figure-callout\; id="0"\; label="I\; P"\; filenames="C20061000083800211.png,C20061000083800212.png"\; state="\{\{state\}\}">I</figure-callout>}}{P_{}}$ Just smaller.That is to say and used identical power but to send fewer information, wasted power.

Summary of the invention

The invention provides a kind of discrete multi-audio frequency modulation data transmitting method and system, in order to the initial constant high problem of transmission error rates that causes of line speed in the transfer of data that solves the Discrete multi-tone modulation that exists in the prior art.

The inventive method comprises:

A kind of discrete multi-audio frequency modulation data transmitting method comprises:

A, transmitting terminal generate first table of bits according to the line speed scheme of data message to be sent, and described first table of bits comprises each circuit carry data information when this sends data;

B, transmitting terminal are sent to receiving terminal according to first table of bits after with data-modulated;

C, receiving terminal carry out demodulation according to first table of bits, obtain corresponding data.

Described line speed scheme adopts calculus of finite differences to describe.

Described method comprises that also receiving terminal obtains the step of the first table of bits information.

Described receiving terminal obtains the first table of bits information, calculates according to bits of original table information via and obtains.

In the described steps A, comprise that also transmitting terminal is sent to receiving terminal by first data channel with the line speed scheme that this sends data message; Receiving terminal utilizes described line speed scheme, obtains first table of bits.

In the described steps A, comprise also generating first gain table that the list item of described first gain table is corresponding with the list item of described first table of bits, comprises each circuit amount of gain adjustment when this sends data;

Among the described step B, comprise that also transmitting terminal is according to the adjustment that gains of described first gain table;

Among the described step C, comprise that also receiving terminal is according to the described first gain table demodulating data.

In the described steps A, in described first table of bits, also comprise the first circuit beared information;

Among the described step C, carry out automatic gain control according to the described first circuit beared information.

The described first circuit beared information immobilizes.

System of the present invention comprises:

A kind of data transmission system of Discrete multi-tone modulation comprises transmitting terminal and receiving terminal,

Described transmitting terminal comprises bits of original table unit, coding unit and transmitting element, coding unit according to bits of original table unit information with digital coding after, be sent to receiving terminal through transmitting element;

Described receiving terminal comprises receiving element, decoding unit and bits of original table unit, and receiving element is decoded according to bits of original table unit information by decoding unit after receiving data, obtains corresponding data;

Described transmitting terminal also comprises:

Line speed scheme determining unit is used for determining that carrying sends the line speed scheme of data;

The transmitting terminal first table of bits unit links to each other with line speed scheme determining unit, according to sending data desired rate information, dynamically generates first table of bits;

Described coding unit according to the first table of bits unit information with digital coding after, be sent to receiving terminal through transmitting element;

Described receiving terminal also comprises:

The receiving terminal first table of bits unit according to rate of received data information, dynamically generates first table of bits;

Receiving element is decoded according to the first table of bits unit information by decoding unit after receiving data, obtains corresponding data.

Described transmitting terminal also comprises:

Data rate counting unit links to each other with line speed scheme determining unit, is used to add up the rate information that transmitting terminal sends;

Determine the line speed unit, link to each other, be used for determining line speed with data rate counting unit.

Described transmitting terminal also comprises:

The transmitting terminal first gain table unit is used for dynamically generating first gain table according to described first table of bits, is used to adjust the transmitting terminal transmitted power.

Described receiving terminal also comprises:

The receiving terminal first gain table unit is used for dynamically generating first gain table according to described first table of bits, is used to adjust the receiving terminal received power.

Described receiving terminal also comprises:

The line speed determining unit is used for determining to receive the data desired rate, makes the receiving terminal first table of bits unit generate first table of bits.

Described receiving terminal also comprises:

Automatic gain control unit links to each other with receiving element, is used to carry out automatic gain control.

Beneficial effect of the present invention is as follows:

The data transmission method of DMT modulation system provided by the invention and system, by the variable circuit carry data information of dynamic bit table (BIT table) carrying, the transmitted power of line speed and circuit is adjusted according to circuit information transmitted rate is dynamic, instant, can reduce transmission error rates, and when saving power resource, reduce crosstalking between circuit.

The present invention proposes can make transceiver be in the optimized state of IPR all the time by demand change BIT table, GAIN table.In time adjust according to dynamic BIT table and GAIN table information, also solved the problem of power resource waste.Can reduce simultaneously with crosstalking between the bundle circuit the technical quick problem of upgrading synchronously of transceiver two ends BIT, GAIN table that solved.

Description of drawings

Fig. 1 is the reference configuration schematic diagram of xDSL system in the prior art;

Fig. 2 is the schematic diagram of BIT table in the prior art;

Fig. 3 is the schematic diagram of GAIN table in the prior art;

Fig. 4 is a main flow schematic diagram of the present invention;

Fig. 5 is concrete schematic flow sheet of using of the present invention;

Fig. 6 is the initial BIT list item schematic diagram of determining during the circuit initialization among the present invention program;

Fig. 7 is the dynamic BIT list item schematic diagram after the present invention ordering;

An ordering schematic diagram behind the line speed that Fig. 8 determines for the present invention program;

Fig. 9 is the schematic diagram that data send in the prior art;

Figure 10 is the schematic diagram that data send among the present invention program;

Figure 11 is the sending end structure schematic diagram of Discrete multi-tone modulated data transmitting of the present invention system;

Figure 12 is the receiving terminal structural representation of Discrete multi-tone modulated data transmitting of the present invention system.

Embodiment

Below in conjunction with Figure of description the specific embodiment of the present invention is described.

Core concept of the present invention is the data volume that sends according to need at transmitting terminal, generate dynamic BIT table, be used in these circuit carrying data, transmitting terminal is according to this dynamic BIT contents in table, circuit loaded information amount can be saved power resource like this when transmitting terminal is adjusted the transmission data immediately.

The BIT table is a Bit Allocation in Discrete table, and DMT (OFDM (OFDM Orthogonalfrequency division multiplexing)) is divided into plurality of sub-bands (also being TONE) to the whole frequency band of circuit, and is mutually orthogonal between each sub-band.Utilize these sub-bands to come transmission information by existing digital modulation technique (the QAM modulation technique of using specific to xDSL).Modulation technique requires to determine its loaded information amount (concrete several bits) according to the noise of each TONE with the power that will send, produces BIT table, gain table (GAIN table) in view of the above.

The whole process that BIT table, GAIN table produce is finished by the xDSL nest plate.These two tables are crucial list items of DMT modulation-demodulation technique.All the time all be stored in the xDSL nest plate.In general, existing product can not changed these two values easily.Because in case change, the technology implementation details of a whole set of physics (PHY) layer all will be done corresponding adjustment.

As shown in Figure 2, be the schematic diagram of a BIT table in the prior art, as seen from the figure, the BIT table comprises NSC-1 list item, all corresponding carrying BIT information of each list item.

Shown in 3, be the schematic diagram of a GAIN table corresponding with BIT epiphase among Fig. 2, as seen from the figure, it comprises NSC-1 list item, all corresponding gain G AIN adjustment information of each list item.

This BIT list item and GAIN list item meet the correlation standard of ITU-T (G.993.2).In fact no matter the carrying bit number what, each TONE transmitted power (P _i) basic identical.Be each TONE's All be not quite similar b _iMore little, IPR is more little.If when therefore actual data rate is lower than line speed, should reduce or close the lower TONE of bit bearing ratio earlier.

As shown in Figure 4, be main flow schematic diagram of the present invention, as seen from the figure, mainly may further comprise the steps:

S1, transmitting terminal generate dynamic BIT table according to sending data, and described dynamic BIT list item comprises each sub-band (TONE) loaded information amount when this sends data;

At transmitting terminal, according to the line speed scheme that will send data message being determined dynamic BIT table, this dynamic BIT list item, each circuit loaded information amount when sending data for this.Above-mentioned information might be different from the information of initial BIT list item, by this adjustment, can make transmitting terminal flexibly, this each sub-band (TONE) loaded information amount when sending data of reasonable configuration, to reach the purpose of saving power resource.

For simplicity, this line speed scheme can adopt calculus of finite differences to describe, and when line speed determines to reach the adjustment of BIT list item so each time, directly can draw rapidly according to difference component.

S2, transmitting terminal will be sent to receiving terminal according to dynamic BIT table after the data-modulated;

After dynamically the BIT table is determined, transmitting terminal will send data according to this dynamic BIT contents in table and modulate the back transmission and get final product.

S3, receiving terminal carry out demodulation according to dynamic BIT table, obtain corresponding data.

After the data that the receiving terminal receiving end/sending end sends, carry out corresponding demodulation according to dynamic BIT list item after, can obtain corresponding data content.

In above-mentioned flow process, can also dynamically generate a dynamic GAIN table at transmitting terminal, this dynamic GAIN list item is corresponding with described dynamic BIT epiphase, comprises each circuit amount of gain adjustment when this sends data;

In step S2 and S3, modulate transmission and demodulation with reference to this GAIN list item respectively accordingly, obtain corresponding data.

In the such scheme, the dynamic BIT table that uses when needing to guarantee the transmitting terminal modulating data and the content of dynamic GAIN table are in full accord, otherwise mistake might appear, guarantee the method that it is consistent, can by an independent data passage line speed scheme that this sends data message be sent to receiving terminal by transmitting terminal; Receiving terminal utilizes described line speed scheme, obtains dynamic BIT table and dynamic GAIN table by modes such as calculating.

Also may relate to receiving terminal in the such scheme and carry out the problem that automatic gain is adjusted, the present invention can be provided with a fixing dynamic line beared information in dynamically BIT shows; This dynamic line beared information content immobilizes, and does not adjust.Carrying out automatic gain control at receiving terminal according to described dynamic line beared information gets final product.

Seeing the concrete application of the transfer of data of a Discrete multi-tone modulation below, in this transfer process, increased contents such as coded modulation, as shown in Figure 5, is schematic flow sheet, as seen from the figure, mainly may further comprise the steps:

S11, transmitting terminal are added up the data transfer rate of reality, determine line speed R _s

R in this step _sNeed smaller or equal to initialized line speed R ₀

S12, transmitting terminal are according to line speed R _sDetermine the line speed scheme, and generate dynamic BIT table (BIT _New) show (GAIN with dynamic GAIN _New).

S13, transmitting terminal are according to dynamic BIT table (BIT _New) encode.

The scheme of this coding can same as the prior artly be handled.

S14, transmitting terminal are after adding the line speed scheme information on the basis of S13, according to dynamic GAIN table (GAIN _New) adjustment gains; And after functional modules such as FFT, send.

S15, receiving terminal receive data, after functions such as equilibrium, A/D, FFT, demodulate the line speed scheme.

S16, receiving terminal generate the dynamic BIT table (BIT consistent with transmitting terminal according to the line speed scheme _New) show (GAIN with dynamic GAIN _New).

By the line speed scheme, can be at the local generation of the receiving terminal dynamic BIT table (BIT consistent with transmitting terminal _New) show (GAIN with dynamic GAIN _New), to guarantee the accurately data that arrive of demodulate reception of receiving terminal.

The S17 receiving terminal is according to dynamic BIT table (BIT _New) and dynamic GAIN table (GAIN _New) finish the recovery of data by relevant criterion.

In the above-mentioned execution mode, each technology point can be handled in the following manner:

1, line speed scheme.

The line speed scheme adopts differential mode, and difference component adopts the dibit position to represent, and is as shown in table 1:

Difference component	00	01	10	11
					Meaning	Constant	Subtract △	Increase △	Rollback

Table 1

In the table 1, R _MinBe minimum line speed; R _MaxBe the highest line speed, the speed of determining when equaling the circuit initialization.Determining of this difference component can draw according to statistical value.The unit of above-mentioned difference component is bit.

In this table 1, the following feature of the circuit output speed after the size of difference component is chosen and regulated has relation, if the difference component value is big, following feature is relatively good, but the variation of the analog signal on the circuit may cause the factors of instability greatly.

This table 1 uses in the following manner:

If through determining after the Information Statistics that difference component is 00 under the constant situation of existing line speed.Keep last line speed.

If determine that after Information Statistics existing line speed should be lower than the line speed of last time, difference component is 01.Line speed reduces a △, if dropped to R _MinThe time, then line speed is R _Min

If determine that after Information Statistics existing line speed should be than the line speed height of last time, difference component is 10.Line speed increases a △, if increased to R _MaxThe time, then line speed is R _Max

If determine that after Information Statistics existing line speed should be high more a lot of than the line speed of last time, difference component is 11.Line speed is disposable to knock-on to R _Max

2, the synchronization scenario of the dynamic BIT table of receiving terminal and transmitting terminal:

After the circuit initialization, generate an initial BIT list item, just determined a line speed according to initial BIT list item.When change took place initial BIT table, corresponding change also can take place in line speed.But the change of transceiver two ends BIT list item must be synchronous, otherwise error of transmission can take place.

At stationary problem, the present invention can give receiving terminal by specific TONE transmission lines speed scheme, the many TONE of general choosing carrying bit.

This special TONE can some be to be used for transmission realization control information of the present invention also, and another part is to be used for transmitting data, and these TONE can be changeless.

3, dynamic BIT list item sequencing schemes:

Fig. 6, Fig. 7 give an example (NSC=24, special TONE are 4,15,16 22) for the ordering of BIT list item, and the initial BIT list item of determining when Fig. 6 is the circuit initialization is to call initial BIT list item in the following text; Fig. 7 is the dynamic BIT list item after sorting.

Ordering can be according to following rule: order is from left to right arranged by the carrying data volume; Carry under the identical situation of data volume and press TONE sequence arrangement from big to small; The carrying data volume is that zero TONE puts in order and do not do requirement; More than the special TONE of Que Dinging is placed on list item backmost, and its order is not done special requirement.

Determine R _MinThe time correspondence dynamic BIT list item, as shown in Figure 8, determine R _MinThe time correspondence the rule of dynamic BIT list item be that the rightmost of the dynamic BIT list item after ordering extracts the part list item that comprises all special TONE at least by order from right to left.

4, according to the initial BIT list item of difference component adjustment.

The difference granularity is meant the bit number that initial BIT list item is adjusted, and below uses the △ symbolic representation.△ can get any one integer in 1 to 15 in the present invention, requires the △ value at transceiver two ends to be consistent.A TONE can be only changed in the change of BIT list item each time, can make things convenient for the simultaneous operation of sending and receiving end like this.

(1) difference component is 00:

Initial BIT list item does not change.

(2) difference component is 01:

At first determine present dynamic BIT list item whether with R _MinCorresponding initial BIT list item unanimity, if consistent, dynamically the BIT list item is not done any adjustment.If inconsistent, the non-vanishing item of high order end of establishing dynamic BIT list item is B _zThen dynamically the value of BIT list item correspondence is $B_n=\left\{\begin{array}{cc}{B}_z-\mathrm{\&Delta;}& B_z>\mathrm{\&Delta;}\\ 0& B_z\&le;\mathrm{\&Delta;}\end{array}\right..$

(3) difference component is 10:

Determine at first whether dynamic BIT list item is consistent with initial BIT list item, if consistent, dynamically the BIT list item is not done any adjustment.If inconsistent, establish dynamic BIT list item first unequal of the low order end of comparing with initial BIT list item and be B _y, item corresponding in the initial BIT list item is B _oThen dynamically the value of BIT list item correspondence is $B_n=\left\{\begin{array}{cc}{B}_o& B_y+\mathrm{\&Delta;}\&GreaterEqual;B_o\\ B_y+\mathrm{\&Delta;}& B_y+\mathrm{\&Delta;}<B_o\end{array}\right..$

(4) difference component is 11:

No matter present dynamic BIT list item is state why, without exception with the initial BIT list item of initial ordering as dynamic BIT list item.

5, the transmission of line speed scheme:

Because the initial BIT list item at transceiver two ends is consistent.Require the dynamic BIT list item at transceiver two ends to adjust synchronously, only need correct transmission difference component to get final product.

Under the general situation, as shown in Figure 9, transmitting terminal is finished sending function by following order:

Data to be sent are done the Trellis coding by initial BIT table;

Data behind the coding are done constellation mapping;

Through the IFFT module, D/A drives grade and is sent to receiving terminal with the data after the mapping;

Receive data in the following order at receiving terminal:

Receive data through amplification, A/D, IFFT module;

Data are carried out the constellation reflection penetrates;

Do the Trellis decoding according to initial BIT table, obtain correct reception data.

As can be seen from Figure 9, if the dynamic BIT list item after the TONE that is used for transmitting difference component through the Trellis coding, can not get upgrading when doing the Trellis decoding according to initial BIT table so in execution graph 9, whole result can make mistakes.The transmission of difference component should be transmitted according to the modular manner of Figure 10, specifically comprises:

At transmitting terminal:

Data to be sent are done the Trellis coding by dynamic BIT table;

Data and difference component behind the coding are done constellation mapping;

Data after the mapping are sent to receiving terminal through IFFT module, D/A, driving etc.;

At receiving terminal:

Receive data through amplification, A/D, FFT module;

Data are carried out the constellation reflection penetrate, and obtain difference component, obtain dynamic BIT table according to difference component;

Do the Trellis decoding according to dynamic BIT table, obtain correct reception data.

Above-mentioned difference component can also can transmit being defined on other TONE in transmission on the pilot tone, but the sending and receiving end both sides must determine as consulting in initialized process by the TONE of certain mechanism synchronization discrepancy component transmission.

6, automatic gain control (AGC) solution:

Transmitted power among the existing xDSL is after initialization is determined, transmitted power is constant substantially.Based on the AGC technology under this condition, obviously can not satisfy the above-mentioned fast-changing transmitted power of data rate of following and compose, therefore, adopt following scheme to solve:

The whole frequency band of transceiver transmission is divided into l section (l ∈ (3,4,5,6,7,8)), the TONE that the carrying bit number is maximum in the initial BIT list item of handle on each section is as special TONE, if there is the bit number of several TONE carryings identical, the TONE that can therefrom choose a close central point is as special TONE.The special TONE that pilot tone (Polit) TONE can be used as AGC uses.

Only make AGC with these special TONE at receiving terminal, as mentioned above, these TONE are once determining that the initial BIT list item of its correspondence, initial GAIN list item all can not change.

7, generate dynamic GAIN list item according to dynamic BIT list item:

When dynamic BIT list item was adjusted according to above-mentioned scheme, the list item of the dynamic GAIN corresponding with dynamic BIT list item also will be done corresponding adjustment.That adjusts is regular as follows:

If adjusted B _n=0, so corresponding G _n=0.

If adjusted B _n≠ 0, so corresponding

$G_n=\left\{\begin{array}{ccc}{G}_o-3(B_n-B_o)& \mathrm{if}& G_o-3(B_n-B_o)\&GreaterEqual;B_{\min }\\ B_{\min }& \mathrm{if}& G_o-3(B_n-B_o)<B_{\min }\end{array}\right.$

Wherein, G _MinMaximum, minimum gain value for correlation standard; G _oBe original GAIN tabular value.

As Figure 11 and shown in Figure 12, be the data transmission system of Discrete multi-tone modulation of the present invention, comprise transmitting terminal 100 and receiving terminal 200.

As shown in figure 11, described transmitting terminal comprises:

Data cell 101 to be sent, initial BIT table unit 102, coding unit 103 and transmitting element 104 after coding unit 103 receives and will send data, are shown information with digital coding according to initial BIT, and are sent to receiving terminal 200 through transmitting element 104;

As shown in figure 12, described receiving terminal 200 comprises:

Receiving element 201, decoding unit 202 and initial BIT table unit 203 after the data that receiving element 201 receiving end/sending ends 100 send, are decoded according to initial BIT table unit 203 information by decoding unit 202, obtain corresponding data;

The present invention has increased the dynamic BIT table unit 105 (204) of transmitting terminal of dynamic adjustment BIT list item information at transmitting terminal 100 and receiving terminal 200 on the such scheme basis, specific as follows:

Be provided with at described transmitting terminal 100:

Line speed scheme determining unit 106 is used for determining that carrying sends the line speed scheme of data;

The dynamic BIT table unit 105 of transmitting terminal links to each other with line speed scheme determining unit 106, is used for generating dynamic BIT table according to determining that carrying sends the line speed scheme of data;

After increasing said two units, described coding unit 102 according to the dynamic BIT information of dynamic BIT table unit 105 with digital coding after, be sent to receiving terminal 200 through transmitting element 103;

Be provided with at described receiving terminal 200:

The dynamic BIT table unit 204 of receiving terminal according to rate of received data information, generates dynamic BIT table;

After increasing said units, after receiving element 201 receives data, decode according to dynamic BIT table unit 204 information, obtain corresponding data by decoding unit 202.

The present invention also is provided with at described transmitting terminal:

Data rate counting unit 107 is used to add up the rate information that transmitting terminal sends;

Transmitting terminal is determined line speed unit 108, is used for determining line speed according to data rate counting unit 107 statisticses;

The dynamic GAIN table unit 109 of transmitting terminal is used for according to the dynamic BIT table unit 105 of described transmitting terminal, dynamically generates dynamic GAIN table.

Be provided with correspondingly with transmitting terminal 100 above-mentioned, also be provided with at described receiving terminal 200:

Receiving terminal line speed scheme determining unit 205 is used for determining to receive the data desired rate;

The dynamic GAIN table unit 206 of receiving terminal is used for according to the dynamic BIT table unit 204 of described receiving terminal, dynamically generates dynamic GAIN table.

Receiving terminal carries out gain controlling for convenience, and the present invention also is provided with automatic gain control unit 207 at receiving terminal, is used to carry out automatic gain control.

Data transmission method and the system of the permanent IPR of the transmission line of DMT modulation system provided by the invention, by the variable circuit carry data information of dynamic BIT table carrying, the transmitted power of line speed and circuit is adjusted according to circuit information transmitted rate is dynamic, instant, can reduce transmission error rates, and when saving power resource, reduce crosstalking between circuit.

Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, if of the present invention these are revised and modification belongs within the scope of claim of the present invention and equivalent technologies thereof, then the present invention also is intended to comprise these changes and modification interior.

Claims (13)

1, a kind of discrete multi-audio frequency modulation data transmitting method is characterized in that, comprising:

A, transmitting terminal generate first table of bits according to the line speed scheme of data message to be sent, and described first table of bits comprises each circuit carry data information when this sends data;

B, transmitting terminal are sent to receiving terminal according to first table of bits after with data-modulated;

C, receiving terminal carry out demodulation according to first table of bits, obtain corresponding data.

2, the method for claim 1 is characterized in that, described line speed scheme adopts calculus of finite differences to describe.

3, the method for claim 1 is characterized in that, comprises that also receiving terminal obtains the step of the first table of bits information.

4, method as claimed in claim 3 is characterized in that, described receiving terminal obtains the first table of bits information, calculates according to bits of original table information via and obtains.

5, as claim 3 or 4 described methods, it is characterized in that, in the described steps A, comprise that also transmitting terminal is sent to receiving terminal by first data channel with the line speed scheme that this sends data message; Receiving terminal utilizes described line speed scheme, obtains first table of bits.

6, the method for claim 1 is characterized in that,

In the described steps A, comprise also generating first gain table that the list item of described first gain table is corresponding with the list item of described first table of bits, comprises each circuit amount of gain adjustment when this sends data;

Among the described step B, comprise that also transmitting terminal is according to the adjustment that gains of described first gain table;

Among the described step C, comprise that also receiving terminal is according to the described first gain table demodulating data.

7, the method for claim 1 is characterized in that,

In the described steps A, in described first table of bits, also comprise the first circuit beared information;

Among the described step C, carry out automatic gain control according to the described first circuit beared information.

8, method as claimed in claim 7 is characterized in that, the described first circuit beared information immobilizes.

9, a kind of data transmission system of Discrete multi-tone modulation comprises transmitting terminal and receiving terminal,

Described transmitting terminal comprises bits of original table unit, coding unit and transmitting element, coding unit according to bits of original table unit information with digital coding after, be sent to receiving terminal through transmitting element;

Described receiving terminal comprises receiving element, decoding unit and bits of original table unit, and receiving element is decoded according to bits of original table unit information by decoding unit after receiving data, obtains corresponding data;

It is characterized in that,

Described transmitting terminal also comprises:

Line speed scheme determining unit is used for determining that carrying sends the line speed scheme of data;

The transmitting terminal first table of bits unit links to each other with line speed scheme determining unit, according to sending data desired rate information, dynamically generates first table of bits;

Described coding unit according to the first table of bits unit information with digital coding after, be sent to receiving terminal through transmitting element;

Described receiving terminal also comprises:

The receiving terminal first table of bits unit according to rate of received data information, dynamically generates first table of bits;

Receiving element is decoded according to the first table of bits unit information by decoding unit after receiving data, obtains corresponding data.

10, system as claimed in claim 9 is characterized in that, described transmitting terminal also comprises:

Data rate counting unit links to each other with line speed scheme determining unit, is used to add up the rate information that transmitting terminal sends;

Determine the line speed unit, link to each other, be used for determining line speed with data rate counting unit.

11, system as claimed in claim 9 is characterized in that,

Described transmitting terminal also comprises:

The transmitting terminal first gain table unit is used for dynamically generating first gain table according to described first table of bits, is used to adjust the transmitting terminal transmitted power.

Described receiving terminal also comprises:

The receiving terminal first gain table unit is used for dynamically generating first gain table according to described first table of bits, is used to adjust the receiving terminal received power.

12, system as claimed in claim 9 is characterized in that, described receiving terminal also comprises:

The line speed determining unit is used for determining to receive the data desired rate, makes the receiving terminal first table of bits unit generate first table of bits.

13, method as claimed in claim 9 is characterized in that, described receiving terminal also comprises:

Automatic gain control unit links to each other with receiving element, is used to carry out automatic gain control.

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